At present, the development of hydrogen production by electrolysis of water has attracted much attention. Due to the characteristics of "cross-border coupling", it is recognized as the booster of clean energy system construction. Traditional hydrogen production methods include natural gas and coal, but it is still difficult to wean itself off fossil fuels. In the past two years, the renewable energy electrolysis water hydrogen production technology has developed strongly. Electrolytic water hydrogen production process is simple and pollution-free, which is considered as a good route for hydrogen production.

As the cost of electricity accounts for about 80% of the total production cost of hydrogen production by hydrolysis, the key to the cost of hydrogen production by hydrolysis is energy consumption. There are two ways to reduce the cost: one is to reduce the energy consumption in the electrolysis process, which can be achieved by developing PEM(proton exchange membrane electrolysis) and SOEC(solid oxide electrolysis) technology; The second is to use low-cost electricity as raw material for hydrogen production, the key lies in the development of photovoltaic and wind power. "At present, the installed scale of new energy in China is growing year by year, far exceeding the carrying capacity of the power grid, and the contradiction between new energy consumption and consumption is prominent. The electricity consumption of waste wind, light and water is increasing year by year, providing favorable conditions for renewable energy to produce hydrogen by electrolysis of water to a certain extent."

According to data released by relevant authorities, China's abandoned wind and photovoltaic power generation capacity was 55.4 billion kilowatt hours in 2018. Using 5 kWh per cubic meter of hydrogen, China's waste wind power can produce 11.08 billion cubic meters of high-purity hydrogen. In terms of hydropower, China's annual abandoned water volume reached 69.1 billion KWH in 2018, with a large surplus of hydropower. "Using electrolytic water to produce hydrogen can effectively alleviate the problem of abandoned water from hydropower. Using surplus hydropower to produce hydrogen, waste water is "turned into treasure", which not only produces hydrogen, but also improves the comprehensive economic benefits of hydropower projects. Hydrogen production from surplus hydropower, photovoltaic and wind power is feasible, but the main reason why it fails to develop on a large scale is the high cost of hydrogen production.

The cost of hydrogen production from coal in China is between 0.8 and 1.2 yuan/standard. The cost of hydrogen production from natural gas is greatly affected by the price of raw materials, and the comprehensive cost is slightly higher than that of hydrogen production from coal. As for hydrogen production by electrolysis of water, the current consumption per cubic meter of hydrogen is about 5-5.5 KWH, so hydrogen production can be realized even with off-peak electricity production and fixed investment other than electricity charges." In terms of water electrolysis equipment, the cost is higher than other hydrogen production methods." In a hydrogen production system of the same scale, the cost of hydrogen production from water electrolysis is about 1.5 times that from natural gas and 3 times that from coal. Compared with other hydrogen production methods, renewable energy electrolysis of water has no price advantage. "In recent years, the amount and volume of electrolysis of water for hydrogen production for renewable energy has increased rapidly. "The enthusiasm is growing, but the scale and exploration is still in its infancy."